The OP admitted nothing of the sort that it isn't personal use. Just because you don't personally consume every bottle doesn't make it not personal use. The primary check for something not being personal use is selling it, which the OP very clearly isn't doing. The point really is that the OP didn't get away with it before, according to CBP the OP did everything perfectly fine before and was doing everything perfectly fine this time. And since when are US CBP stationed in FRA? This isn't an issue like letting a passenger onto a plane that won't be able to gain access to the foreign country where the carrier gets fined. To the best of my knowledge, carriers don't get fined for people's duty violations. CBP confiscates the items and moves on. Which didn't happen here as the OP never made it to CBP.